Bought one pair from crucial.com and i got a 2nd set of individual single 1GB ballistix tracers 2nd hand to make up to a 4GB config

Singles:

CM128M6416T27ZD2T-4YXCDFTL

vs

Dual channel kit:

BL12864L503. 16TD

I emailed crucial to ask about the different code in the left side white label on modules and was told the code depends on the retailer etc i.e. Crucial direct shows L503 etc, while newegg where the singles came from showed ZD2T. The orange label on modules comes from crucial/micron and the PN (crucial terms material #) denotes the memory ICs used.

Crucial confirmed both PN of 51181 use the same Micron ICs

Now both sets do exactly same settings 280-285mhz 3-3-3-8 8-18-2223 1T at 2.76v. So thought I'd try 4x 1GB config with 2T.

To start with for 4GB, in DFI NF4 advance chipset bios section you need to enable PCI MMIO memory hole option to properly map 4GB otherwise you will only see 3GB of memory.